PostgreSQL (+PgBouncer) will be more than enough and actually can reach higher transaction numbers than MongoDB since I doubt you need horizontal scaling for such workload.
It has the added benefit of doing a lot for you. With MongoDB you'll need app logic to do certain things. MongoDB improved ACID support but it's not as smooth as just starting PostgreSQL and use it right away.
But that all doesn't matter. Pick what you're comfortable with.
It has the added benefit of doing a lot for you. With MongoDB you'll need app logic to do certain things. MongoDB improved ACID support but it's not as smooth as just starting PostgreSQL and use it right away.
But that all doesn't matter. Pick what you're comfortable with.